Chapter 12 - Waves 2

Question 1

define superposition

Answer 1

when two waves of equal amplitude and frequency meet and their displacements combine

Question 2

constructive interference

Answer 2

when two waves, which are in phase, collide and their displacements add up

Question 3

destructive interference

Answer 3

when two waves are in anti phase, when one wave is at a peak and another is at a trough, their added displacements make a minimum point

Question 4

coherence

Answer 4

waves with the same frequency and constant phase difference

Question 5

how do waves interfere at a maxima

Answer 5

constructively

Question 6

how do waves interfere at a minima

Answer 6

destructively

Question 7

define path difference

Answer 7

the difference in distance travelled between two waves

Question 8

young’s double slit experiment guide

Answer 8

• double slit
  -distance ‘a’ = slit separation
• shine a coherent light source through slit onto glass screen, at a distance of ‘d’ meters away
• will produce maxima and minima
• measure distance between fringes = ‘x’
• use equation to find wavelength of the light

Question 9

how does a stationary wave form

Answer 9

when two progressive waves with equal frequency, travelling in the same direction are superposed

Question 10

how is a node formed

Answer 10

when two waves are in anti phase, and their displacements cancel out

Question 11

how is an anti-node formed

Answer 11

when two waves are in phase

Question 12

open tubes

Answer 12

must have an anti-node at each end

Question 13

tubes closed at one end

Answer 13

anti-node at open end, node at closed end